Display device

ABSTRACT

A display device includes light emitting elements disposed in pixels; a color conversion layer disposed on the light emitting elements; a color filter layer disposed on the color conversion layer; and a resonant filter disposed between the color conversion layer and the color filter layer. The resonant filter includes a first semi-transmissive layer, a second semi-transmissive layer, and a medium disposed between the first semi-transmissive layer and the second semi-transmissive layer.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority to and benefits of Korean patentapplication 10-2021-0163496 under 35 U.S.C. § 119(a), filed on Nov. 24,2021, in the Korean Intellectual Property Office (KIPO), the entirecontents of which are incorporated herein by reference.

BACKGROUND 1. Technical Field

The disclosure generally relates to a display device.

2. Description of Related Art

Recently, as interest in information displays is increased, research anddevelopment of display devices have been continuously conducted.

SUMMARY

Embodiments provide a display device capable of improving lightefficiency and luminance.

In accordance with an aspect of the disclosure, there is provided adisplay device including light emitting elements disposed in pixels; acolor conversion layer disposed on the light emitting elements; a colorfilter layer disposed on the color conversion layer; and a resonantfilter disposed between the color conversion layer and the color filterlayer, wherein the resonant filter includes a first semi-transmissivelayer, a second semi-transmissive layer, and a medium disposed betweenthe first semi-transmissive layer and the second semi-transmissivelayer.

The pixels may include a first pixel, a second pixel, and a third pixel.The resonant filter may include a first resonant filter disposed in thefirst pixel; and a second resonant filter disposed in the second pixel.

The first resonant filter and/or the second resonant filter may notoverlap the third pixel in a plan view.

The resonant filter may further include a third resonant filteroverlapping the third pixel in a plan view.

A thickness of a medium of the first resonant filter may be differentfrom a thickness of a medium of the second resonant filter.

A thickness of a medium of the first resonant filter may be equal to athickness of a medium of the second resonant filter.

The pixels may include a first pixel emitting light of a first color; asecond pixel emitting light of a second color; and a third pixelemitting light of a third color. The resonant filter may allow thelights of the first to third colors to be selectively reflectedtherefrom or transmitted therethrough.

The resonant filter may allow about 70% or more of the light of thefirst color and/or the light of the second color to be transmittedtherethrough, and allow about 20% or less of the light of the thirdcolor to be transmitted therethrough.

The resonant filter may allow about 10% or less of the light of thefirst color and/or the light of the second color to be reflectedtherefrom, and allow about 60% or more of the light of the third colorto be reflected therefrom.

The medium of the resonant filter may have a refractive index of about2.5 or less.

The first semi-transmissive layer and/or the second semi-transmissivelayer may be a metal thin film.

In accordance with another aspect of the disclosure, there is provided adisplay device including first to third pixels respectively emittinglight of first to third colors; light emitting elements disposed in thefirst to third pixels; a color conversion layer disposed on the lightemitting elements; a color filter layer disposed on the color conversionlayer; a first resonant filter disposed in the first pixel between thecolor conversion layer and the color filter layer; and a second resonantfilter disposed in the second pixel between the color conversion layerand the color filter layer.

The first resonant filter and/or the second resonant filter may allowthe lights of the first to third colors to be selectively reflectedtherefrom or transmitted therethrough.

The first resonant filter and/or the second resonant filter may notoverlap the third pixel.

The display device may further include a third resonant filter disposedin the third pixel between the color conversion layer and the colorfilter layer.

A thickness of the first resonant filter may be different from athickness of the second resonant filter.

A thickness of the first resonant filter may be equal to a thickness ofthe second resonant filter.

The color conversion layer may include a first color conversion layerdisposed in the first pixel; a second color conversion layer disposed inthe second pixel; and a light scattering layer disposed in the thirdpixel.

The light emitting elements may emit the light of the third color.

Each of the light emitting elements may include a first semiconductorlayer, a second semiconductor layer, and an active layer disposedbetween the first semiconductor layer and the second semiconductorlayer.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be more thorough and complete, and will conveythe scope of the example embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.Like reference numerals refer to like elements throughout.

FIG. 1 is a schematic perspective view illustrating a light emittingelement in accordance with an embodiment of the disclosure.

FIG. 2 is a schematic cross-sectional view illustrating the lightemitting element in accordance with the embodiment of the disclosure.

FIG. 3 is a schematic plan view illustrating a display device inaccordance with an embodiment of the disclosure.

FIG. 4 is a schematic diagram of an equivalent circuit illustrating apixel in accordance with an embodiment of the disclosure.

FIG. 5 is a schematic plan view illustrating a pixel in accordance withan embodiment of the disclosure.

FIG. 6 is a schematic cross-sectional view taken along line A-A′ shownin FIG. 5 .

FIG. 7 is a schematic cross-sectional view taken along line B-B′ shownin FIG. 5 .

FIG. 8 is a schematic cross-sectional view illustrating first to thirdpixels in accordance with an embodiment of the disclosure.

FIGS. 9 to 11 are schematic cross-sectional views illustrating aresonant filter.

FIG. 12 is a schematic cross-sectional view illustrating first to thirdpixels in accordance with an embodiment of the disclosure.

FIGS. 13 to 15 are sectional views illustrating a resonant filter.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The effects and characteristics of the disclosure and a method ofachieving the effects and characteristics will be clear by referring tothe embodiments described below in detail together with the accompanyingdrawings. However, the disclosure is not limited to the embodimentsdisclosed herein but may be implemented in various forms. Theembodiments are provided by way of example only so that a person ofordinary skilled in the art can understand the features in thedisclosure and the scope thereof. Therefore, the disclosure can bedefined by the scope of the appended claims.

The terminology used herein is for the purpose of describing particularembodiments only and is not construed as limiting the disclosure. Asused herein, the singular forms are intended to include the plural forms(or meanings) as well, unless the context clearly indicates otherwise.The terms “comprises/includes” and/or “comprising/including,” when usedin this specification, specify the presence of mentioned component,step, operation and/or element, but do not exclude the presence oraddition of one or more other components, steps, operations and/orelements.

When described as that any element is “connected”, “coupled” or“accessed” to another element, it should be understood that it ispossible that still another element may “connected”, “coupled” or“accessed” between the two elements as well as that the two elements aredirectly “connected”, “coupled” or “accessed” to each other. It will beunderstood that the terms “contact,” “connected to,” and “coupled to”may include a physical and/or electrical contact, connection, orcoupling.

The term “on” that is used to designate that an element or layer is onanother element or layer includes both a case where an element or layeris located directly on another element or layer, and a case where anelement or layer is located on another element or layer via stillanother element layer. Like reference numerals generally denote likeelements throughout the specification.

It will be understood that, although the terms “first,” “second,” andthe like may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another element. Thus, a “first” elementdiscussed below could also be termed a “second” element withoutdeparting from the teachings of the disclosure.

The terms “about” or “approximately” as used herein is inclusive of thestated value and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” may mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

In the specification and the claims, the term “and/or” is intended toinclude any combination of the terms “and” and “or” for the purpose ofits meaning and interpretation. For example, “A and/or B” may beunderstood to mean “A, B, or A and B.” The terms “and” and “or” may beused in the conjunctive or disjunctive sense and may be understood to beequivalent to “and/or.” The phrase “at least one of” is intended toinclude the meaning of “at least one selected from the group of” for thepurpose of its meaning and interpretation. For example, “at least one ofA and B” may be understood to mean “A, B, or A and B.”

Unless otherwise defined or implied herein, all terms (includingtechnical and scientific terms) used herein have the same meaning ascommonly understood by those skilled in the art to which this disclosurepertains. It will be further understood that terms, such as thosedefined in commonly used dictionaries, should be interpreted as having ameaning that is consistent with their meaning in the context of therelevant art and the disclosure, and should not be interpreted in anideal or excessively formal sense unless clearly so defined herein.

Hereinafter, embodiments of the disclosure will be described in moredetail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view illustrating a light emittingelement in accordance with an embodiment of the disclosure. FIG. 2 is aschematic sectional view illustrating the light emitting element inaccordance with the embodiment of the disclosure. Although FIGS. 1 and 2illustrate a pillar-shaped light emitting element LD, the kind and/orshape of the light emitting element LD is not limited thereto.

Referring to FIGS. 1 and 2 , the light emitting element LD may include afirst semiconductor layer 11, an active layer 12, a second semiconductorlayer 13, and/or an electrode layer 14.

The light emitting element LD may be provided in a pillar shapeextending in a direction. The light emitting element LD may have a firstend portion EP1 and a second end portion EP2. One of the first andsecond semiconductor layers 11 and 13 may be disposed at the first endportion EP1 of the light emitting element LD. The other of the first andsecond semiconductor layers 11 and 13 may be disposed at the second endportion EP2 of the light emitting element LD. For example, the firstsemiconductor layer 11 may be disposed at the first end portion EP1 ofthe light emitting element LD, and the second semiconductor layer 13 maybe disposed at the second end portion EP2 of the light emitting elementLD.

In some embodiments, the light emitting element LD may be a lightemitting element manufactured in a pillar shape through an etchingprocess, etc. In this specification, the term “pillar shape” may includea rod- or bar-like shape of which an aspect ratio is greater than 1,such as a cylinder or a polyprism, and the shape of its section is notparticularly limited.

The light emitting element LD may have a size small to a degree of thenanometer scale to the micrometer scale. In an example, the lightemitting element LD may have a diameter D (or width) in a range of thenanometer scale to the micrometer scale and/or a length L in a range ofthe nanometer scale to the micrometer scale. However, the size of thelight emitting element LD is not limited thereto, and the size of thelight emitting element LD may be variously changed according to designconditions of various types of devices, e.g., a display device, and thelike, which use, as a light source, a light emitting device using thelight emitting element LD.

The first semiconductor layer 11 may be a first conductivity typesemiconductor layer. For example, the first semiconductor layer 11 mayinclude a p-type semiconductor layer. In an example, the firstsemiconductor layer 11 may include at least one semiconductor materialamong InAIGaN, GaN, AlGaN, InGaN, AlN, and InN, and include a p-typesemiconductor layer doped with a first conductivity type dopant such asMg. However, the material forming (or constituting) the firstsemiconductor layer 11 is not limited thereto. In addition, the firstsemiconductor layer 11 may be configured with various materials.

The active layer 12 may be disposed between the first semiconductorlayer 11 and the second semiconductor layer 13. The active layer 12 mayinclude a structure among a single well structure, a multi-wellstructure, a single quantum well structure, a multi-quantum well (MQW)structure, a quantum dot structure, and a quantum wire structure, butthe disclosure is not limited thereto. The active layer 12 may includeGaN, InGaN, InAIGaN, AlGaN, AlN, or the like. In addition, the activelayer 12 may be configured with various materials.

In case that a voltage which is a threshold voltage or more is appliedto ends (e.g., both ends) of the light emitting element LD, the lightemitting element LD emits light as electron-hole pairs are combined inthe active layer 12. The light emission of the light emitting element LDis controlled by using such a principle, so that the light emittingelement LD can be used as a light source for various light emittingdevices, including a pixel of a display device.

The second semiconductor layer 13 is formed on the active layer 12, andmay include a semiconductor layer having a type different from that ofthe first semiconductor layer 11. For example, the second semiconductorlayer 13 may include an n-type semiconductor layer. In an example, thesecond semiconductor layer 13 may include any semiconductor materialamong InAIGaN, GaN, AlGaN, InGaN, AlN, and InN, and include an n-typesemiconductor layer doped with a second conductivity type dopant such asSi, Ge, or Sn. However, the material constituting the secondsemiconductor layer 13 is not limited thereto. In addition, the secondsemiconductor layer 13 may be configured with various materials.

The electrode layer 14 may be disposed on the first end portion EP1and/or the second end portion EP2 of the light emitting element LD.Although FIG. 2 illustrates, as an example, a case where the electrodelayer 14 is formed on the first semiconductor layer 11, the disclosureis not limited thereto. For example, a separate electrode layer may befurther disposed on the second semiconductor layer 13.

The electrode layer 14 may include a transparent metal or a transparentmetal oxide. In an example, the electrode layer 14 may include at leastone of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide(ZnO), and zinc tin oxide (ZTO), but the disclosure is not limitedthereto. In case that the electrode layer 14 may be made of atransparent metal or a transparent metal oxide, light generated in theactive layer 12 of the light emitting element LD may pass through theelectrode layer 14 and be emitted to the outside of the light emittingelement LD.

An insulative film INF may be provided on a surface of the lightemitting element LD. The insulative film INF may be disposed directly onsurfaces of the first semiconductor layer 11, the active layer 12, thesecond semiconductor layer 13, and/or the electrode layer 14. Theinsulative film INF may expose the first and second end portions EP1 andEP2 of the light emitting element LD, which have different polarities.In some embodiments, the insulative film INF may expose a side portionof the electrode layer 14 and/or the second semiconductor layer 13,adjacent to the first and second end portions EP1 and EP2 of the lightemitting element LD.

The insulative film INF may prevent an electrical short circuit whichmay occur in case that the active layer 12 contacts (or is in contactwith) a conductive material except the first and second semiconductorlayers 11 and 13. Also, the insulative film INF may minimize a surfacedefect of light emitting elements LD, thereby the lifespan and lightemission efficiency of the light emitting elements LD.

The insulative film INF may include at least one of silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y)),aluminum nitride (AlN_(x)), aluminum oxide (AlO_(x)), zirconium oxide(ZrO_(x)), hafnium oxide (HfO_(x)), and titanium oxide (TiO_(x)). Forexample, the insulative film INF may be configured as a double layer,and layers constituting the double layer may include differentmaterials. In an example, the insulative film INF may be configured as adouble layer including aluminum oxide (AlO_(x)) and silicon oxide(SiO_(x)), but the disclosure is not limited thereto. In someembodiments, the insulative film INF may be omitted.

A light emitting device including the above-described light emittingelement LD may be used in various kinds of devices which require a lightsource, including a display device. For example, light emitting elementsLD may be disposed in each pixel of a display panel, and be used as alight source of each pixel. However, the application field of the lightemitting element LD is not limited to the above-described example. Forexample, the light emitting element LD may be used in other types ofdevices that require a light source, such as a lighting device.

FIG. 3 is a schematic plan view illustrating a display device inaccordance with an embodiment of the disclosure.

FIG. 3 illustrates a display device, particularly, a display panel PNLprovided in the display device as an example of an electronic devicewhich can use, as a light source, the light emitting element LDdescribed in the embodiment shown in FIGS. 1 and 2 .

For convenience of description, FIG. 3 briefly illustrates a structureof the display panel PNL, focusing on a display area DA. However, insome embodiments, at least one driving circuit (e.g., at least one of ascan driver and a data driver), lines, and/or pads, which are not shownin the drawing, may be further disposed in the display panel PNL.

Referring to FIG. 3 , the display panel PNL and a base layer BSL forforming the same may include the display area DA for displaying an imageand a non-display area NDA except the display area DA. The display areamay form a screen on which the image is displayed, and the non-displayarea NDA may be the other area except the display area DA.

A pixel part (or pixel unit) PXU may be disposed in the display area DA.The pixel part PXU may include a first pixel PXL1, a second pixel PXL2,and/or a third pixel PXL3. Hereinafter, in case that at least one pixelamong the first pixel PXL1, the second pixel PXL2, and the third pixelPXL3 is arbitrarily designated or in case that two or more kinds ofpixels among the first pixel PXL1, the second pixel PXL2, and the thirdpixel PXL3 are inclusively designated, the corresponding pixel or thecorresponding pixels will be referred to as a “pixel PXL” or “pixelsPXL.”

The pixels PXL may be regularly arranged according to a stripestructure, a PENTILE™ structure, or the like. However, the arrangementstructure of the pixels PXL is not limited thereto, and the pixels PXLmay be arranged in the display area DA by using various structuresand/or methods.

In some embodiments, two or more kinds of pixels PXL emitting lights ofdifferent colors may be disposed in the display area DA. In an example,first pixels PXL1 emitting light of a first color, second pixels PXL2emitting light of a second color, and third pixels PXL3 emitting lightof a third color may be arranged in the display area DA. At least onefirst pixel PXL1, at least one second pixel PXL2, and at least one thirdpixel PXL3, which are disposed adjacent to each other, may constitute apixel part PXU capable of emitting lights of various colors. Forexample, each of the first to third pixels PXL1, PXL2, and PXL3 may be apixel emitting light of a color (e.g., a predetermined or selectedcolor). In some embodiments, the first pixel PXL1 may be a red pixelemitting light of red, the second pixel PXL2 may be a green pixelemitting light of green, and the third pixel PXL3 may be a blue pixelemitting light of blue. However, the disclosure is not limited thereto.

In an embodiment, the first pixel PXL1, the second pixel PXL2, and thethird pixel PXL3 have light emitting elements emitting light of a samecolor, and may include color conversion layers and/or color filters ofdifferent colors, which are disposed on the respective light emittingelements, to respectively emit lights of the first color, the secondcolor, and the third color. In an embodiment, the first pixel PXL1, thesecond pixel PXL2, and the third pixel PXL3 respectively have, as lightsources, a light emitting element of the first color, a light emittingelement of the second color, and a light emitting element of the thirdcolor, so that the light emitting elements can respectively emit lightsof the first color, the second color, and the third color. However, thecolor, kind, and/or number of pixels PXL constituting each pixel partPXU are not particularly limited. In an example, the color of lightemitted by each pixel PXL may be variously changed.

The pixel PXL may include at least one light source driven by a controlsignal (e.g., a scan signal and a data signal) and/or a power source(e.g., a first power source and a second power source). In anembodiment, the light source may include at least one light emittingelement LD in accordance with the embodiment shown in FIGS. 1 and 2 ,e.g., a subminiature pillar-shaped light emitting element LD having asize small to a degree of the nanometer scale to the micrometer scale.However, the disclosure is not limited thereto. In addition, varioustypes of light emitting elements LD may be used as the light source ofthe pixel PXL.

In an embodiment, each pixel PXL may be configured as an active pixel.However, the kind, structure, and/or driving method of pixels PXL whichcan be applied to the display device are not particularly limited. Forexample, each pixel PXL may be configured as a pixel of a passive oractive light emitting display device using various structures and/ordriving methods.

FIG. 4 is a schematic diagram of an equivalent circuit illustrating apixel in accordance with an embodiment of the disclosure.

In some embodiments, the pixel PXL shown in FIG. 4 may be one of thefirst pixel PXL1, the second pixel PXL2, and the third pixel PXL3, whichare provided in the display panel PNL shown in FIG. 3 . The first pixelPXL1, the second pixel PXL2, and the third pixel PXL3 may havestructures substantially identical or similar to one another.

Referring to FIG. 4 , the pixel PXL may include a light emitting part(or light emitting unit) EMU for generating light with a luminancecorresponding to a data signal and a pixel circuit PXC for driving thelight emitting part EMU.

The pixel circuit PXC may be connected between a first power source VDDand the light emitting part EMU. Also, the pixel circuit PXC may beconnected to a scan line SL and a data line DL of the correspondingpixel PXL to control an operation of the light emitting part EMU,corresponding to a scan signal and a data signal, which are suppliedfrom the scan line SL and the data line DL. Also, the pixel circuit PXCmay be selectively further connected to a sensing signal line SSL and asensing line SENL.

The pixel circuit PXC may include at least one transistor and acapacitor. For example, the pixel circuit PXC may include a firsttransistor M1, a second transistor M2, a third transistor M3, and astorage capacitor Cst.

The first transistor M1 may be connected between the first power sourceVDD and a first connection electrode ELT1. A gate electrode of the firsttransistor M1 is connected to a first node N1. The first transistor M1may control a driving current supplied to the light emitting part EMU,corresponding to a voltage of the first node N1. For example, the firsttransistor M1 may be a driving transistor for controlling the drivingcurrent of the pixel PXL.

In an embodiment, the first transistor M1 may selectively include alower conductive layer BML (also referred to as a “lower electrode,” a“back gate electrode,” or a “lower light blocking layer”). The gateelectrode and the lower conductive layer BML of the first transistor M1may overlap each other with an insulating layer interposed therebetween.In an embodiment, the lower conductive layer BML may be connected to one(or first) electrode, e.g., a source or drain electrode of the firsttransistor M1.

In case that the first transistor M1 includes the lower conductive layerBML, there may be applied a back-biasing technique (or sync technique)for moving a threshold voltage of the first transistor M1 in a negativeor positive direction by applying a back-biasing voltage to the lowerconductive layer BML of the first transistor M1 in driving the pixelPXL. In an example, a source-sync technique is applied by connecting thelower conductive layer BML to a source electrode of the first transistorM1, so that the threshold voltage of the first transistor M1 can bemoved in the negative or positive direction. In addition, in case thatthe lower conductive layer BML is disposed on the bottom of asemiconductor pattern forming a channel of the first transistor M1, thelower conductive layer BML severs as a light blocking pattern, therebystabilizing operational characteristics of the first transistor M1.However, the function and/or application method of the lower conductivelayer BML is not limited thereto.

The second transistor M2 may be connected between the data line DL andthe first node N1. In addition, a gate electrode of the secondtransistor M2 is connected to the scan line SL. The second transistor M2is turned on in case that a scan signal having a gate-on voltage (e.g.,a high-level voltage) is supplied from the scan line SL, to connect thedata line DL and the first node N1 to each other.

A data signal of a corresponding frame may be supplied to the data lineDL for each frame period. The data signal may be transferred to thefirst node N1 through the turned-on second transistor M2 during a periodin which the scan signal having the gate-on voltage is supplied. Forexample, the second transistor M2 may be a switching transistor fortransferring each data signal to the inside of the pixel PXL.

A first electrode of the storage capacitor Cst may be connected to thefirst node N1, and a second electrode of the storage capacitor Cst maybe connected to a second electrode of the first transistor M1. Thestorage capacitor Cst is charged with a voltage corresponding to thedata signal supplied to the first node N1 during each frame period.

The third transistor M3 may be connected between the first connectionelectrode ELT1 (or the second electrode of the first transistor M1) andthe sensing line SENL. In addition, a gate electrode of the thirdtransistor M3 may be connected to the sensing signal line SSL. The thirdtransistor M3 may transfer a voltage value, applied to the firstconnection electrode ELT1, to the sensing line SENL according to asensing signal supplied to the sensing signal line SSL. The voltagevalue transferred through the sensing line SENL may be provided to anexternal circuit (e.g., a timing controller), and the external circuitmay extract characteristic information (e.g., the threshold voltage ofthe first transistor M1, etc.), based on the provided voltage value. Theextracted characteristic information may be used to convert image datasuch that a characteristic deviation between the pixels PXL iscompensated.

Although FIG. 4 illustrates that the transistors included in the pixelcircuit PXC are an n-type transistor, the disclosure is not limitedthereto. For example, at least one of the first, second, and thirdtransistors M1, M2, and M3 may be changed to a p-type transistor.

In addition, the structure and driving method of the pixel PXL may bevariously changed in some embodiments. For example, the pixel circuitPXC may be configured as a pixel circuit having various structuresand/or various driving methods, in addition to the embodiment shown inFIG. 4 .

In an example, the pixel circuit PXC may not include the thirdtransistor M3. Also, the pixel circuit PXC may further include othercircuit elements such as a compensation transistor for compensating forthe threshold voltage of the first transistor M1, etc., aninitialization transistor for initializing a voltage of the first nodeN1 and/or the first connection electrode ELT1, an emission controltransistor for controlling a period in which a driving current issupplied to the light emitting part EMU, and/or a boosting capacitor forboosting the voltage of the first node N1.

The light emitting part EMU may include at least one light emittingelement LD, e.g., light emitting elements LD connected to each otherbetween the first power source VDD and a second power source VSS.

For example, the light emitting part EMU may include the firstconnection electrode ELT1 connected to the first power source VDDthrough the pixel circuit PXC and a first power line PL1, a fifthconnection electrode ELT5 connected to the second power source VSSthrough a second power line PL2, and light emitting elements LDconnected to each other between the first and fifth connectionelectrodes ELT1 and ELT5.

The first power source VDD and the second power source VSS may havedifferent potentials such that the light emitting elements LD can emitlight. In an example, the first power source VDD may be set as ahigh-potential power source, and the second power source VSS may be setas a low-potential power source.

In an embodiment, the light emitting part EMU may include at least oneserial stage. Each serial stage may include a pair of electrodes (e.g.,two electrodes) and at least one light emitting element LD connected ina forward direction between the pair of electrodes. The number of serialstages constituting the light emitting part EMU and the number of lightemitting elements LD constituting each serial stage are not particularlylimited. In an example, the numbers of light emitting elements LDconstituting the respective serial stages may be equal to or differentfrom each other, and the number of light emitting elements LD is notparticularly limited.

For example, the light emitting part EMU may include a first serialstage including at least one first light emitting element LD1, a secondserial stage including at least one second light emitting element LD2, athird serial stage including at least one third light emitting elementLD3, and a fourth serial stage including at least one fourth lightemitting element LD4.

The first serial stage may include the first connection electrode ELT1,a second connection electrode ELT2, and at least one first lightemitting element LD1 connected to each other between the first andsecond connection electrodes ELT1 and ELT2. Each first light emittingelement LD1 may be connected in the forward direction between the firstand second connection electrodes ELT1 and ELT2. For example, a first endportion EP1 of the first light emitting element LD1 may be connected tothe first connection electrode ELT1, and a second end portion EP2 of thefirst light emitting element LD1 may be connected to the secondconnection electrode ELT2.

The second serial stage may include the second connection electrode ELT2and a third connection electrode ELT3, and at least one second lightemitting elements LD2 connected to each other between the second andthird connection electrodes ELT2 and ELT3. Each second light emittingelement LD2 may be connected in the forward direction between the secondand third connection electrodes ELT2 and ELT3. For example, a first endportion EP1 of the second light emitting element LD2 may be connected tothe second connection electrode ELT2, and a second end portion EP2 ofthe second light emitting element LD2 may be connected to the thirdconnection electrode ELT3.

The third serial stage may include the third connection electrode ELT3and a fourth connection electrode ELT4, and at least one third lightemitting elements LD3 connected to each other between the third andfourth connection electrodes ELT3 and ELT4. Each third light emittingelement LD3 may be connected in the forward direction between the thirdand fourth connection electrodes ELT3 and ELT4. For example, a first endportion EP1 of the third light emitting element LD3 may be connected tothe third connection electrode ELT3, and a second end portion EP2 of thethird light emitting element LD3 may be connected to the fourthconnection electrode ELT4.

The fourth serial stage may include the fourth connection electrode ELT4and the fifth connection electrode ELT5, and at least one fourth lightemitting elements LD4 connected to each other between the fourth andfifth connection electrodes ELT4 and ELT5. Each fourth light emittingelement LD4 may be connected in the forward direction between the fourthand fifth connection electrodes ELT4 and ELT5. For example, a first endportion EP1 of the fourth light emitting element LD4 may be connected tothe fourth connection electrode ELT4, and a second end portion EP2 ofthe fourth light emitting element LD4 may be connected to the fifthconnection electrode ELT5.

A first electrode, e.g., the first connection electrode ELT1 of thelight emitting part EMU may be an anode electrode of the light emittingpart EMU. A last electrode, e.g., the fifth connection electrode ELT5 ofthe light emitting part EMU may be a cathode electrode of the lightemitting part EMU.

The other electrodes, e.g., the second connection electrode ELT2, thethird connection electrode ELT3, and/or the fourth connection electrodeELT4 of the light emitting part EMU may constitute respectiveintermediate electrodes. For example, the second connection electrodeELT2 may form a first intermediate electrode IET1, the third connectionelectrode ELT3 may form a second intermediate electrode IET2, and thefourth connection electrode ELT4 may form a third intermediate electrodeIET3.

In case that light emitting elements LD are connected to each other in aseries-parallel structure, power efficiency can be improved as comparedwith when light emitting elements LD of which the number is equal tothat of the above-described light emitting elements LD are connected toeach other only in parallel. In addition, in the pixel in which thelight emitting elements LD are connected to each other in theseries-parallel structure, although a short defect (or short circuitdefect) or the like occurs in some serial stages, a luminance (e.g., apredetermined or selected luminance) can be expressed through lightemitting elements LD of the other serial stage. Hence, the probabilitythat a dark spot defect will occur in the pixel PXL can be reduced.However, the disclosure is not limited thereto, and the light emittingpart EMU may be configured by connecting the light emitting elements LDto each other only in series or by connecting the light emittingelements LD to each other only in parallel.

Each of the light emitting element LD may include a first end portionEP1 (e.g., a p-type end portion) connected to the first power source VDDvia at least one electrode (e.g., the first connection electrode ELT1),the pixel circuit PXC, and/or the first power line PL1, and a second endportion EP2 (e.g., an n-type end portion) connected to the second powersource VSS via at least another electrode (e.g., the fifth connectionelectrode ELT5) and the second power line PL2. For example, the lightemitting elements LD may be connected to each other in the forwarddirection between the first power source VDD and the second power sourceVSS. The light emitting elements LD connected to each other in theforward direction may constitute effective light sources of the lightemitting part EMU.

In case that a driving current is supplied through the correspondingpixel circuit PXC, the light emitting elements LD may emit light with aluminance corresponding to the driving current. For example, during eachframe period, the pixel circuit PXC may supply, to the light emittingpart EMU, a driving current corresponding to a grayscale value to beexpressed in a corresponding frame. Accordingly, while the lightemitting elements LD emit light with the luminance corresponding to thedriving current, the light emitting part EMU can express the luminancecorresponding to the driving current.

FIG. 5 is a schematic plan view illustrating a pixel in accordance withan embodiment of the disclosure. FIG. 6 is a schematic sectional viewtaken along line A-A′ shown in FIG. 5 . FIG. 7 is a schematic sectionalview taken along line B-B′ shown in FIG. 5 .

In an example, the pixel PXL shown in FIG. 5 may be one of the first tothird pixels PXL1, PXL2, and PXL3 constituting the pixel part PXU shownin FIG. 3 , and the first to third pixels PXL1, PXL2, and PXL3 may havestructures substantially identical or similar to one another. Inaddition, although FIG. 5 illustrates an embodiment in which each pixelPXL includes light emitting elements LD disposed in four serial stagesas shown in FIG. 4 , the number of serial stages of each pixel PXL maybe variously changed in some embodiments.

Hereinafter, in case that at least one of first to fourth light emittingelements LD1, LD2, LD3, and LD4 is arbitrarily designated or in casethat two or more kinds of light emitting elements are inclusivelydesignated, the corresponding light emitting element or thecorresponding light emitting elements will be referred to as a “lightemitting element LD” or “light emitting elements LD.” In addition, incase that at least one electrode among electrodes including first tofourth electrodes ALE1, ALE2, ALE3, and ALE4 is arbitrarily designatedor in case that two or more kinds of electrodes are inclusivelydesignated, the corresponding electrode or the corresponding electrodeswill be referred to as an “electrode ALE” or “electrodes ALE.” In casethat at least one connection electrode among connection electrodesincluding first to fifth connection electrodes ELT1, ELT2, ELT3, ELT4,and ELT5 is arbitrarily designated or in case that two or more kinds ofconnection electrodes are inclusively designated, the correspondingconnection electrode or the corresponding connection electrodes will bereferred to as a “connection electrode ELT” or “connection electrodesELT.”

Referring to FIG. 5 , each pixel PXL may include an emission area EA anda non-emission area NEA. The emission area EA may be an area includinglight emitting elements LD to emit light. The non-emission area NEA maybe disposed to surround the emission area EA. The non-emission area NEAmay be an area in which a bank BNK surrounding the emission area EA isprovided. The bank BNK may include openings OPA including a firstopening area OPA1 overlapping the emission area EA and a second openingarea OPA2 overlapping the non-emission area NEA.

Each pixel PXL may include electrodes ALE, light emitting elements LD,and/or connection electrodes ELT. The electrodes ALE may be provided inat least the emission area EA. The electrodes ALE may extend in a seconddirection (Y-axis direction), and be spaced apart from each other in afirst direction (X-axis direction). The electrodes ALE may extend fromthe emission area EA to the non-emission area NEA. For example, theelectrodes ALE may extend from the emission area EA to the secondopening area OPA2. Each of the first to fourth electrodes ALE1, ALE2,ALE3, and ALE4 may extend in the second direction (Y-axis direction),and be spaced apart from each other in the first direction (X-axisdirection) to be sequentially disposed.

Some of the electrodes ALE may be connected to the pixel circuit PXC(see FIG. 4 ) and/or a power line. For example, the first electrode ALE1may be connected to the pixel circuit PXC and/or the first power linePL1, and the third electrode ALE3 may be connected to the second powerline PL2.

In some embodiments, some of the electrodes ALE may be electricallyconnected to some of the connection electrodes ELT through contact holesCH. For example, the first electrode ALE1 may be electrically connectedto the first connection electrode ELT1 through a first contact hole CH1,the second electrode ELT2 may be electrically connected to the secondconnection electrode ELT2 through a second contact hole CH2, the thirdelectrode ALE3 may be electrically connected to the fifth connectionelectrode ELT5 through a third contact hole CH3, and the fourthelectrode ELT4 may be electrically connected to the fourth connectionelectrode ELT4 through a fourth contact hole CH4. The first to fourthcontact holes CH1, CH2, CH3, and CH4 may be located in the secondopening area OPA2, but the disclosure is not limited thereto.

A pair of electrodes ALE adjacent to each other may be supplied withdifferent signals in a process of aligning the light emitting elementsLD. For example, in case that the first to fourth electrodes ALE1, ALE2,ALE3, and ALE4 are sequentially arranged in the first direction (X-axisdirection) in the emission area EA, the first and second electrodes ALE1and ALE2 may form a pair to be supplied with different alignmentsignals, and the third and fourth electrodes ALE3 and ALE4 may form apair to be supplied with different alignment signals.

In an embodiment, the second and third electrodes ALE2 and ALE3 may besupplied with a same signal in the process of aligning the lightemitting elements LD. Although FIG. 5 illustrates that the second andthird electrodes ALE2 and ALE3 are separated from each other, the secondand third electrodes ALE2 and ALE3 may be integrally or non-integrallyconnected to each other in the process of aligning the light emittingelements LD.

In some embodiments, bank patterns BNP may be disposed on the bottom ofthe electrodes ALE. The bank patterns BNP may include a first bankpattern BNP1, a second bank pattern BNP2, and a third bank pattern BNP3.The bank patterns BNP may be provided in at least the emission area EA.The bank patterns BNP may extend in the second direction (Y-axisdirection), and be spaced apart from each other in the first direction(X-axis direction).

In case that each of the bank patterns BNP is provided on the bottom ofone area of each of the electrodes ALE, one area of each of theelectrodes ALE may protrude in an upward direction of the pixel PXL, forexample, a third direction (Z-axis direction) in an area in which eachof the bank patterns BNP is formed. In case that the bank patterns BNPand/or the electrodes ALE include a reflective material, a reflectivewall structure may be formed at the periphery of the light emittingelements LD. Accordingly, light emitted from the light emitting elementsLD can be emitted in the upward direction of the pixel PXL (e.g., afront direction of the display panel PNL, including a viewing anglerange (e.g., a predetermined or selected viewing angle range)), and thusthe light emission efficiency of the display panel PNL can be improved.

Each of the light emitting elements LD may be aligned between a pair ofelectrodes ALE in the emission area EA. Also, each of the light emittingelements LD may be electrically connected between a pair of connectionelectrodes ELT.

The first light emitting element LD1 may be aligned between the firstand second electrodes ALE1 and ALE2. The first light emitting elementLD1 may be electrically connected between the first and secondconnection electrodes ELT1 and ELT2. In an example, the first lightemitting element LD1 may be aligned in a first area (e.g., an upper endarea) of the first and second electrodes ALE1 and ALE2. A first endportion EP1 of the first light emitting element LD1 may be electricallyconnected to the first connection electrode ELT1, and a second endportion EP2 of the first light emitting element LD1 may be electricallyconnected to the second connection electrode ELT2.

The second light emitting element LD2 may be aligned between the firstand second electrodes ALE1 and ALE2. The second light emitting elementLD2 may be electrically connected between the second and thirdconnection electrodes ELT2 and ELT3. In an example, the second lightemitting element LD2 may be aligned in a second area (e.g., a lower endarea) of the first and second electrodes ALE1 and ALE2. A first endportion EP1 of the second light emitting element LD2 may be electricallyconnected to the second connection electrode ELT2, and a second endportion EP2 of the second light emitting element LD2 may be electricallyconnected to the third connection electrode ELT3.

The third light emitting element LD3 may be aligned between the thirdand fourth electrodes ALE3 and ALE4. The third light emitting elementLD3 may be electrically connected between the third and fourthconnection electrodes ELT3 and ELT4. In an example, the third lightemitting element LD3 may be aligned in a second area (e.g., a lower endarea) of the third and fourth electrodes ALE3 and ALE4. A first endportion EP1 of the third light emitting element LD3 may be electricallyconnected to the third connection electrode ELT3, and a second endportion EP2 of the third light emitting element LD3 may be electricallyconnected to the fourth connection electrode ELT4.

The fourth light emitting element LD4 may be aligned between the thirdand fourth electrodes ALE3 and ALE4. The fourth light emitting elementLD4 may be electrically connected between the fourth and fifthconnection electrodes ELT4 and ELT5. In an example, the fourth lightemitting element LD4 may be aligned in a first area (e.g., an upper endarea) of the third and fourth electrodes ALE3 and ALE4. A first endportion EP1 of the fourth light emitting element LD4 may be electricallyconnected to the fourth connection electrode ELT4, and a second endportion EP2 of the fourth light emitting element LD4 may be electricallyconnected to the fifth connection electrode ELT5.

In an example, the first light emitting element LD1 may be located in aleft upper end area of the emission area EA, and the second lightemitting element LD2 may be located in a left lower end area of theemission area EA. The third light emitting elements LD3 may be locatedat a right lower end area of the emission area EA, and the fourth lightemitting element LD4 may be located in a right upper end area of theemission area EA. However, the arrangement and/or connection structureof the light emitting elements LD may be variously changed according tothe structure of the light emitting part EMU and/or the number of serialstages.

Each of the connection electrodes ELT may be provided in at least theemission area EA, and be disposed to overlap at least one electrode ALEand/or at least one light emitting element LD. For example, each of theconnection electrodes ELT may be formed on the electrodes ALE and/or thelight emitting elements LD to overlap the electrodes ALE and/or thelight emitting elements LD. Therefore, each of the electrodes ELT may beelectrically connected to the light emitting elements LD.

The first connection electrode ELT1 may be disposed on the first area(e.g., the upper end area) of the first electrode ALE1 and the first endportions EP1 of the first light emitting elements LD1, to beelectrically connected to the first end portions EP1 of the first lightemitting elements LD1.

The second connection electrode ELT2 may be disposed on the first area(e.g., the upper end area) of the second electrode ALE2 and the secondend portions EP2 of the first light emitting elements LD1, to beelectrically connected to the second end portions EP2 of the first lightemitting elements LD1. Also, the second connection electrode ELT2 may bedisposed on the second area (e.g., the lower end area) of the firstelectrode ALE1 and the first end portions EP1 of the second lightemitting elements LD2, to be electrically connected to the first endportions EP1 of the second light emitting elements LD2. For example, thesecond connection electrode ELT2 may electrically connect the second endportions EP2 of the first light emitting elements LD1 and the first endportions EP1 of the second light emitting elements LD2 to each other inthe emission area EA. To this end, the second connection electrode ELT2may have a bent shape. For example, the second connection electrode ELT2may have a structure bent or curved at a boundary between an area inwhich at least one first light emitting element LD1 is arranged and anarea in which at least one second light emitting element LD2 isarranged.

The third connection electrode ELT3 may be disposed on the second area(e.g., the lower end area) of the second electrode ALE2 and the secondend portions EP2 of the second light emitting elements LD2, to beelectrically connected to the second end portions EP2 of the secondlight emitting elements LD2. Also, the third connection electrode ELT3may be disposed on the second area (e.g., the lower end area) of thefourth electrode ALE4 and the first end portions EP1 of the third lightemitting elements LD3, to be electrically connected to the first endportions EP1 of the third light emitting elements LD3. For example, thethird connection electrode ELT3 may electrically connect the second endportions EP2 of the second light emitting elements LD2 and the first endportions EP1 of the third light emitting elements LD3 to each other inthe emission area EA. To this end, the third connection electrode ELT3may have a bent shape. For example, the third connection electrode ELT3may have a structure bent or curved at a boundary between an area inwhich at least one second light emitting element LD2 is arranged and anarea in which at least one third light emitting element LD3 is arranged.

The fourth connection electrode ELT3 may be disposed on the second area(e.g., the lower end area) of the third electrode ALE3 and the secondend portions EP2 of the third light emitting elements LD3, to beelectrically connected to the second end portions EP2 of the third lightemitting elements LD3. Also, the fourth connection electrode ELT4 may bedisposed on the first area (e.g., the upper end area) of the fourthelectrode ALE4 and the first end portions EP1 of the fourth lightemitting elements LD4, to be electrically connected to the first endportions EP1 of the fourth light emitting elements LD4. For example, thefourth connection electrode ELT4 may electrically connect the second endportions EP2 of the third light emitting elements LD3 and the first endportions EP1 of the fourth light emitting elements LD4 to each other inthe emission area EA. To this end, the fourth connection electrode ELT4may have a bent shape. For example, the fourth connection electrode ELT4may have a structure bent or curved at a boundary between an area inwhich at least one third light emitting element LD3 is arranged and anarea in which at least one fourth light emitting element LD4 isarranged.

The fifth connection electrode ELT5 may be disposed on the first area(e.g., the upper end area) of the third electrode ALE3 and the secondend portions EP2 of the fourth light emitting elements LD4, to beelectrically connected to the second end portions EP2 of the fourthlight emitting elements LD4.

In the above-described manner, the light emitting elements LD alignedbetween the electrodes ALE may be connected to each other in a desiredform by using the connection electrodes ELT. For example, the firstlight emitting elements LD1, the second light emitting elements LD2, thethird light emitting elements LD3, and the fourth light emittingelements LD4 may be sequentially connected to each other in series byusing the connection electrodes ELT.

Hereinafter, focusing on a light emitting element LD, a sectionalstructure of each pixel PXL will be described in detail with referenceto FIGS. 6 and 7 . FIGS. 6 and 7 illustrate a pixel circuit layer PCLand a light emitting element layer LEL. FIG. 7 illustrates firsttransistor M1 among various circuit elements constituting the pixelcircuit PXC (see FIG. 4 ). In case that the first to third transistorsM1, M2, and M3 are designated without being distinguished from eachother, each of the first to third transistors M1, M2, and M3 will beinclusively referred to as a “transistor M.” The structure oftransistors M and/or the positions of the transistors M for each layeris not limited to the embodiment shown in FIG. 7 , and may be variouslychanged in some embodiments.

Referring to FIGS. 6 and 7 , the pixel circuit layer PCL and the lightemitting element layer LEL of the pixel PXL in accordance with theembodiment of the disclosure may include circuit elements includingtransistors M disposed on a base layer BSL and various lines connectedthereto. The light emitting element layer LEL including electrodes ALE,light emitting elements LD, and/or connection electrodes ELT may bedisposed on the pixel circuit layer PCL.

The base layer BSL may be a rigid or flexible substrate or a film. In anexample, the base layer BSL may be a rigid substrate made of glass ortempered glass, a flexible substrate (or thin film) made of a plastic ormetal material, or at least one insulating layer. The material and/orproperty of the base layer BSL is not particularly limited. In anembodiment, the base layer BSL may be substantially transparent. Thephrase “substantially transparent” may mean that light can betransmitted with a transmittance or more. In an embodiment, the baselayer BSL may be translucent or opaque. Also, the base layer BSL mayinclude a reflective material in some embodiments.

A lower conductive layer BML and a first power conductive layer PL2 amay be disposed on the base layer BSL. The lower conductive layer BMLand the first power conductive layer PL2 a may be disposed in a samelayer. For example, the lower conductive layer BML and the first powerconductive layer PL2 a may be simultaneously formed through a sameprocess, but the disclosure is not limited thereto. The first powerconductive layer PL2 a may form the second power line PL2 described withreference to FIG. 4 and the like.

Each of the lower conductive layer BML and the first power conductivelayer PL2 a may be formed as a single layer or a multi-layer, which ismade of at least one of molybdenum (Mo), copper (Cu), aluminum (Al),chromium (Cr), gold (Au), silver (Ag), titanium (Ti), nickel (Ni),neodymium (Nd), indium (In), tin (Sn), and any oxide or ally thereof.

A buffer layer BFL may be disposed over the lower conductive layer BMLand the first power conductive layer PL2 a. The buffer layer BFL mayprevent an impurity from being diffused into each circuit element. Thebuffer layer BFL may be configured as a single layer, and may also beconfigured as a multi-layer including at least two layers. In case thatthe buffer layer BFL is provided as the multi-layer, the layers may beformed of a same material or be formed of different materials.

A semiconductor pattern SCP may be disposed on the buffer layer BFL. Inan example, the semiconductor pattern SCP may include a first region incontact with a first transistor electrode TE1, a second region incontact with a second transistor electrode ET2, and a channel regionlocated between the first and second regions. In some embodiments, oneof the first and second regions may be a source region, and the other ofthe first and second regions may be a drain region.

In some embodiments, the semiconductor pattern SCP may be made ofpolysilicon, amorphous silicon, oxide semiconductor, etc. In addition,the channel region of the semiconductor pattern SCP is a semiconductorpattern undoped with an impurity, and may be an intrinsic semiconductor.Each of the first and second regions of the semiconductor pattern SCPmay be a semiconductor pattern doped with an impurity.

A gate insulating layer GI may be disposed on the buffer layer BFL andthe semiconductor pattern SCP. In an example, the gate insulating layerGI may be disposed between the semiconductor pattern SCP and a gateelectrode GE. Also, the gate insulating layer GI may be disposed betweenthe buffer layer BFL and a second power conductive layer PL2 b. The gateinsulating layer GI may be configured as a single layer or amulti-layer, and include various kinds of inorganic insulatingmaterials, including silicon oxide (SiO_(x)), silicon nitride (SiN_(x)),silicon oxynitride (SiO_(x)N_(y)), aluminum nitride (AlN_(x)), aluminumoxide (AlO_(x)), zirconium oxide (ZrO_(x)), hafnium oxide (HfO_(x)), andtitanium oxide (TiO_(x)).

The gate electrode GE of the transistor M and the second powerconductive layer PL2 b may be disposed on the gate insulating layer GI.For example, the gate electrode GE and the second power conductive layerPL2 b may be disposed in a same layer. For example, the gate electrodeGE and the second power conductive layer PL2 b may be simultaneouslyformed through a same process, but the disclosure is not limitedthereto. The gate electrode GE may be disposed on the gate insulatinglayer GI to overlap the semiconductor pattern SCP in the third direction(Z-axis direction). The second power conductive layer PL2 b may bedisposed on the gate insulating layer GI to overlap the first powerconductive layer PL2 a in the third direction (Z-axis direction). Thesecond power conductive layer PL2 b along with the first powerconductive layer PL2 a may constitute the second power line PL2described with reference to FIG. 4 and the like.

Each of the gate electrode GE and the second power conductive layer PL2b may be formed as a single layer or a multi-layer, which is made ofmolybdenum (Mo), copper (Cu), aluminum (Al), chromium (Cr), gold (Au),silver (Ag), titanium (Ti), nickel (Ni), neodymium (Nd), indium (In),tin (Sn), and any oxide or alloy thereof.

An interlayer insulating layer ILD may be disposed over the gateelectrode GE and the second power conductive layer PL2 b. In an example,the interlayer insulating layer ILD may be disposed between the gateelectrode GE and the first and second transistor electrodes TE1 and TE2.Also, the interlayer insulating layer ILD may be disposed between thesecond power conductive layer PL2 b and a third power conductive layerPL2 c.

The interlayer insulating layer ILD may be configured as a single layeror a multi-layer, and include various kinds of inorganic insulatingmaterials, including silicon oxide (SiO_(x)), silicon nitride (SiN_(x)),silicon oxynitride (SiO_(x)N_(y)), aluminum nitride (AlN_(x)), aluminumoxide (AlO_(x)), zirconium oxide (ZrO_(x)), hafnium oxide (HfO_(x)), andtitanium oxide (TiO_(x)).

The first and second transistor electrodes TE1 and TE2 of the transistorM and the third power conductive layer PL2 c may be disposed on theinterlayer insulating layer ILD. The first and second transistorelectrodes TE1 and TE2 and the third power conductive layer PL2 c may bedisposed in a same layer. For example, the first and second transistorelectrodes TE1 and TE2 and the third power conductive layer PL2 c may besimultaneously formed through a same process, but the disclosure is notlimited thereto.

The first and second transistor electrodes TE1 and TE2 may be disposedto overlap the semiconductor pattern SCP in the third direction (Z-axisdirection). The first and second transistor electrodes TE1 and TE2 maybe electrically connected to the semiconductor pattern SCP. For example,the first transistor electrode TE1 may be electrically connected to thefirst region of the semiconductor pattern SCP through a contact holepenetrating the interlayer insulating layer ILD. Also, the firsttransistor electrode TE1 may be electrically connected to the lowerconductive layer BML through a contact hole penetrating the interlayerinsulating layer ILD and the buffer layer BFL. The second transistorelectrode TE2 may be electrically connected to the second region of thesemiconductor pattern SCP through a contact hole penetrating theinterlayer insulating layer ILD. In some embodiments, any of the firstand second transistor electrodes TE1 and TE2 may be a source electrode,and the other of the first and second transistor electrodes TE1 and TE2may be a drain electrode.

The third power conductive layer PLC2 c may be disposed to overlap thefirst power conductive layer PL2 a and/or the second power conductivelayer PL2 b in the third direction (Z-axis direction). The third powerconductive layer PL2 c may be electrically connected to the first powerconductive layer PL2 a and/or the second power conductive layer PL2 b.For example, the third power conductive layer PL2 c may be electricallyconnected to the first power conductive layer PL2 a through a contacthole penetrating the interlayer insulating layer ILD and the bufferlayer BFL. Also, the third power conductive layer PL2 c may beelectrically connected to the second power conductive layer PL2 bthrough a contact hole penetrating the interlayer insulating layer ILD.The third power conductive layer PL2 c along with the first powerconductive layer PL2 a and/or the second power conductive layer PL2 bmay constitute the second power line PL2 described with reference toFIG. 4 and the like.

The first and second transistor electrodes TE1 and TE2 and the thirdpower conductive layer PL2 c may be formed as a single layer or amulti-layer, which is made of molybdenum (Mo), copper (Cu), aluminum(Al), chromium (Cr), gold (Au), silver (Ag), titanium (Ti), nickel (Ni),neodymium (Nd), indium (In), tin (Sn), and any oxide or alloy thereof.

A protective layer PSV may be disposed over the first and secondtransistor electrodes TE1 and TE2 and the third power conductive layerPL2 c. The protective layer PSV may be configured as a single layer or amulti-layer, and include various kinds of inorganic insulatingmaterials, including silicon oxide (SiO_(x)), silicon nitride (SiN_(x)),silicon oxynitride (SiO_(x)N_(y)), aluminum nitride (AlN_(x)), aluminumoxide (AlO_(x)), zirconium oxide (ZrO_(x)), hafnium oxide (HfO_(x)), andtitanium oxide (TiO_(x)).

A via layer VIA may be disposed on the protective layer PSV. The vialayer VIA may be made of an organic material to planarize a lower stepdifference. For example, the via layer VIA may include an organicmaterial such as acrylic resin, epoxy resin, phenolic resin, polyamidesresin, polyimides resin, polyester resin, polyphenylene sulfide resin,or benzocyclobutene (BCB). However, the disclosure is not limitedthereto, and the via layer VIA may include various kinds of inorganicinsulating materials, including silicon oxide (SiO_(x)), silicon nitride(SiN_(x)), silicon oxynitride (SiO_(x)N_(y)), aluminum nitride(AlN_(x)), aluminum oxide (AlO_(x)), zirconium oxide (ZrO_(x)), hafniumoxide (HfO_(x)), and titanium oxide (TiO_(x)).

Bank patterns BNP of the light emitting element layer LEL may bedisposed on the via layer VIA of the pixel circuit layer PCL. In someembodiments, the bank patterns BNP may have various shapes. In anembodiment, the bank patterns BNP may have a shape protruding in thethird direction (Z-axis direction) on the base layer BSL. Also, the bankpatterns BNP may have an inclined surface inclined at an angle (e.g., apredetermined or selected angle) with respect to the base layer BSL.However, the disclosure is not limited thereto, and the bank patternsBNP may have a sidewall having a curved shape, a stepped shape, or thelike. In an example, the bank patterns BNP may have a section having asemicircular shape, a semi-elliptical shape, or the like.

Electrodes and insulating layers, which are disposed on the top of thebank patterns BNP, may have a shape corresponding to the bank patternsBNP. In an example, electrodes ALE disposed on the patterns BNP mayinclude an inclined surface or a curved surface, which has a shapecorresponding to that of the bank patterns BNP. Accordingly, the bankpatterns BNP along with the electrodes ALE provided on the top thereofmay serve as a reflective member for guiding light, emitted from lightemitting elements LD, in a front direction of the pixel PXL, forexample, the third direction (Z-axis direction), thereby improving thelight emission efficiency of the display panel PNL.

The bank patterns BNP may include at least one organic material and/orat least one inorganic material. In an example, the bank patterns BNPmay include an organic material such as acrylic resin, epoxy resin,phenolic resin, polyamide resin, polyimide resin, polyester resin,polyphenylene sulfide resin, or benzocyclobutene (BCB). However, thedisclosure is not limited thereto, and the patterns BNP may includevarious kinds of inorganic insulating materials, including silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y)),aluminum nitride (AlN_(x)), aluminum oxide (AlO_(x)), zirconium oxide(ZrO_(x)), hafnium oxide (HfO_(x)), and titanium oxide (TiO_(x)).

The electrodes ALE may be disposed on the via layer VIA and the bankpatterns BNP. The electrodes ALE may be disposed to be spaced apart fromeach other in the pixel PXL. The electrodes ALE may be disposed in asame layer. The electrodes ALE may be simultaneously formed through asame process, but the disclosure is not limited thereto.

The electrodes ALE may be supplied with an alignment signal in a processof aligning the light emitting elements LD. Accordingly, an electricfiled is formed between the electrodes ALE, so that the light emittingelements LD provided in each pixel PXL can be aligned between theelectrodes ALE.

The electrodes ALE may include at least one conductive material. In anexample, the electrodes ALE may include at least one metal among variousmetallic materials including silver (Ag), magnesium (Mg), aluminum (Al),platinum (Pt), palladium (Pd), gold (Au), silver (Ag), nickel (Ni),neodymium (Nd), iridium (Ir), chromium (Cr), titanium (Ti), molybdenum(Mo), copper (Cu), and the like, or any alloy including the at least onemetal, at least one conductive oxide such as indium tin oxide (ITO),indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO),aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), zinctin oxide (ZTO), or gallium tin oxide (GTO), and the like, and at leastone conductive material among conductive polymers such aspoly(3,4-ethylenedioxythiophene) (PEDOT), but the disclosure is notlimited thereto.

A first insulating layer INS1 may be disposed over the electrodes ALE.The first insulating layer INS1 may be configured as a single layer or amulti-layer, and include various kinds of inorganic insulating materialsincluding silicon oxide (SiO_(x)), silicon nitride (SiN_(x)), siliconoxynitride (SiO_(x)N_(y)), aluminum nitride (AlN_(x)), aluminum oxide(AlO_(x)), zirconium oxide (ZrO_(x)), hafnium oxide (HfO_(x)), andtitanium oxide (TiO_(x)).

A bank BNK may be disposed on the first insulating layer INS1. The bankBNK may form a dam structure defining an emission area in which lightemitting elements LD are to be supplied in a process of supplying thelight emitting elements LD to each of the pixels PXL. For example, adesired kind and/or amount of light emitting element ink may be suppliedto the area defined by the bank BNK.

The bank BNK may include an organic material such as acrylic resin,epoxy resin, phenolic resin, polyamide resin, polyimide resin, polyesterresin, polyphenylene sulfide resin, or benzocyclobutene (BCB). However,the disclosure is not limited thereto, and the bank BNK may includevarious kinds of inorganic insulating materials including silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y)),aluminum nitride (AlN_(x)), aluminum oxide (AlO_(x)), zirconium oxide(ZrO_(x)), hafnium oxide (HfO_(x)), and titanium oxide (TiO_(x)).

In some embodiments, the bank BNK may include at least one lightblocking material and/or at least one reflective material. Accordingly,light leakage between adjacent pixels PXL can be prevented. For example,the bank BNK may include at least one black matrix material and/or atleast one color filter material. In an example, the bank BNK may beformed as a black opaque pattern capable of blocking transmission oflight. In an embodiment, a reflective layer or the like may be formed ona surface (e.g., a sidewall) of the bank BNK to increase the lightefficiency of each pixel PXL.

The light emitting elements LD may be disposed on the first insulatinglayer INS1. The light emitting elements LD may be disposed between theelectrodes ALE on the first insulating layer INS1. The light emittingelements LD may be prepared in a form in which the light emittingelements LD are dispersed in a light emitting element ink, to besupplied to each of the pixels PXL through an inkjet printing process orthe like. In an example, the light emitting elements LD may be dispersedin a volatile solvent to be provided to each pixel PXL. Subsequently, incase that an alignment signal is supplied to the electrodes ALE, thelight emitting elements LD may be aligned between the electrodes ALE,while an electric field is formed between the electrodes ALE. After thelight emitting elements LD are aligned, the solvent may be volatilizedor removed through other processes, so that the light emitting elementsLD can be stably arranged between the electrodes ALE.

A second insulating layer INS2 may be disposed on the light emittingelements LD. For example, the second insulating layer INS2 may bepartially provided on the light emitting elements LD, and expose firstand second end portions EP1 and EP2 of the light emitting elements LD.In case that the second insulating layer INS2 is formed on the lightemitting elements LD after the alignment of the light emitting elementsLD is completed, the light emitting elements LD can be prevented frombeing separated from a position at which the light emitting elements LDare aligned.

The second insulating layer INS2 may be configured as a single layer ora multi-layer, and include various kinds of inorganic insulatingmaterials including silicon oxide (SiO_(x)), silicon nitride (SiN_(x)),silicon oxynitride (SiO_(x)N_(y)), aluminum nitride (AlN_(x)), aluminumoxide (AlO_(x)), zirconium oxide (ZrO_(x)), hafnium oxide (HfO_(x)), andtitanium oxide (TiO_(x)).

The connection electrodes ELT may be disposed on the first and secondend portions EP1 and EP2 of the light emitting elements LD, which areexposed by the second insulating layer INS2. The connection electrodesELT may be disposed in a same layer. For example, the connectionelectrodes ELT may be configured as a same conductive layer. Theconnection electrodes ELT may be simultaneously formed through a sameprocess. The connection electrodes ELT may be separated as individualconnection electrodes ELT by forming a conductive layer on the lightemitting element LD and partially removing the conductive layer formedon the second insulating layer INS2. However, the disclosure is notlimited thereto, and some of the connection electrodes ELT may be formedin different conductive layers.

A first connection electrode ELT1 may be directly disposed on first endportions EP1 of first light emitting elements LD1, to contact the firstend portions EP1 of the first light emitting elements LD1.

In addition, a second connection electrode ELT2 may be directly disposedon second end portions EP2 of the first light emitting elements LD1, tocontact the second end portions EP2 of the first light emitting elementsLD1. Also, the second connection electrode ELT2 may be directly disposedon first end portions of second light emitting elements LD2, to contactthe first end portions EP1 of the second light emitting elements LD2.For example, the second connection electrode ELT2 may electricallyconnect the second end portions EP2 of the first light emitting elementsLD1 and the first end portions EP1 of the second light emitting elementsLD2 to each other.

Similarly, a third connection electrode ELT3 may be directly disposed onsecond end portions EP2 of the second light emitting elements LD2, tocontact the second end portions EP2 of the second light emittingelements LD2. Also, the third connection electrode ELT3 may be directlydisposed on first end portions EP1 of third light emitting elements LD3,to contact the first end portions EP1 of the third light emittingelements LD3. For example, the third connection electrode ELT3 mayelectrically connect the second end portions EP2 of the second lightemitting elements LD2 and the first end portions EP1 of the third lightemitting elements LD3 to each other.

Similarly, a fourth connection electrode ELT4 may be directly disposedon second end portions EP2 of the third light emitting elements LD3, tocontact the second end portions EP2 of the third light emitting elementsLD3. Also, the fourth connection electrode ELT4 may be directly disposedon first end portions EP1 of the fourth light emitting elements LD4, tocontact the first end portions EP1 of the fourth light emitting elementsLD4. For example, the fourth connection electrode ELT4 may electricallyconnect the second end portions EP2 of the third light emitting elementsLD3 and the first end portions EP1 of the fourth light emitting elementsLD4 to each other.

Similarly, a fifth connection electrode ELT5 may be directly disposed onsecond end portions EP2 of the fourth light emitting elements LD4, tocontact the second end portions EP2 of the fourth light emittingelements LD4.

The connection electrodes ELT may be made of various transparentconductive materials. In an example, the connection electrodes ELT mayinclude at least one of various transparent conductive materialsincluding indium tin oxide (ITO), indium zinc oxide (IZO), indium tinzinc oxide (ITZO), zinc oxide (ZnO), aluminum-doped zinc oxide (AZO),gallium-doped zinc oxide (GZO), zinc tin oxide (ZTO), or gallium tinoxide (GTO), and may be implemented substantially transparently ortranslucently to satisfy a transmittance (e.g., a predetermined orselected transmittance). Accordingly, light emitted from the first andsecond end portions EP1 and EP2 of the light emitting elements LD can beemitted to the outside of the display panel PNL while passing throughthe connection electrodes ELT.

FIG. 8 is a schematic sectional view illustrating first to third pixelsin accordance with an embodiment of the disclosure. FIGS. 9 to 11 areschematic sectional views illustrating a resonant filter.

FIG. 8 illustrates a partition wall WL, a color conversion layer CCL, acolor filter layer CFL, and/or an overcoat layer OC which are providedon the pixel circuit layer PCL and the light emitting element layer LELof the pixel PXL described with reference to FIGS. 6 and 7 .

Referring to FIG. 8 , the partition wall may be disposed on the lightemitting element layer LEL of the first to third pixels PXL1, PXL2, andPXL3. In an example, the partition wall WL may be disposed between thefirst to third pixels PXL1, PXL2, and PXL3 or at a boundary between thefirst to third pixels PXL1, PXL2, and PXL3, and include an openingoverlapping each of the first to third pixels PXL1, PXL2, and PXL3. Theopening of the partition wall WL may provide a space in which the colorconversion layer CCL can be provided.

The partition wall WL may include an organic material such as acrylicresin, epoxy resin, phenolic resin, polyamide resin, polyimide resin,polyester resin, polyphenylene sulfide resin, or benzocyclobutene (BCB).However, the disclosure is not limited thereto, and the partition wallWL may include various kinds of inorganic insulating materials includingsilicon oxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiO_(x)N_(y)), aluminum nitride (AlN_(x)), aluminum oxide (AlO_(x)),zirconium oxide (ZrO_(x)), hafnium oxide (HfO_(x)), and titanium oxide(TiO_(x)).

In some embodiments, the partition wall WL may include at least onelight blocking and/or at least one reflective material. Accordingly,light leakage between adjacent pixels PXL can be prevented. For example,the partition wall WL may include at least one black matrix materialand/or at least one color filter material. In an example, the partitionwall WL may be formed as a black opaque pattern capable of blockingtransmission of light. In an embodiment, a reflective layer (not shown)or the like may be formed on a surface (e.g., a sidewall) of thepartition wall WL so as to improve the light efficiency of each pixelPXL.

The color conversion layer CCL may be disposed on the light emittingelement layer EL including the light emitting elements LD in the openingof the partition wall WL. The color conversion layer CCL may include afirst color conversion layer CCL1 disposed in the first pixel PXL1, asecond color conversion layer CCL2 disposed in the second pixel PXL2,and a light scattering layer LSL disposed in the third pixel PXL3.

In an embodiment, the first to third pixels PXL1, PXL2, and PXL3 mayinclude light emitting elements LD emitting light of a same color. Forexample, the first to third pixels PXL1, PXL2, and PXL3 may includelight emitting elements LD emitting light of a third color (or blue).The color conversion layer CCL including color conversion particles isdisposed on each of the first to third pixels PXL1, PXL2, and PXL3, sothat a full-color image can be displayed.

The first color conversion layer CCL1 may include first color conversionparticles for converting light of the third color, which is emitted fromthe light emitting element LD, into light of a first color. For example,the first color conversion layer CCL1 may include first quantum dots QD1dispersed in a matrix material such as base resin.

In an embodiment, in case that the light emitting element LD is a bluelight emitting element emitting light of blue, and the first pixel PXL1is a red pixel, the first color conversion layer CCL1 may include afirst quantum dot QD1 for converting light of blue, which is emittedfrom the blue light emitting element, into light of red. The firstquantum dot QD1 may absorb blue light and emit red light by shifting awavelength of the blue light according to energy transition. In casethat the first pixel PXL1 is a pixel of another color, the first colorconversion layer CCL1 may include a first quantum dot QD1 correspondingto the color of the first pixel PXL1.

The second color conversion layer CCL2 may include second colorconversion particles for converting light of the third color, which isemitted from the light emitting element LD, into light of a secondcolor. For example, the second color conversion layer CCL2 may includesecond quantum dots QD2 dispersed in a matrix material such as baseresin.

In an embodiment, in case that the light emitting element LD is a bluelight emitting element emitting light of blue, and the second pixel PXL2is a green pixel, the second color conversion layer CCL2 may include asecond quantum dot QD2 for converting light of blue, which is emittedfrom the blue light emitting element, into light of green. The secondquantum dot QD2 may absorb blue light and emit green light by shifting awavelength of the blue light according to energy transition. In casethat the second pixel PXL2 is a pixel of another color, the second colorconversion layer CCL2 may include a second quantum dot QD2 correspondingto the color of the second pixel PXL2.

In an embodiment, light of blue having a relatively short wavelength ina visible light band is incident into the first quantum dot QD1 and thesecond quantum dot QD2, so that absorption coefficients of the firstquantum dot QD1 and the second quantum dot QD2 can be increased.Accordingly, the efficiency of light finally emitted from the firstpixel PXL1 and the second pixel PXL2 can be improved, and excellentcolor reproduction can be ensured. In addition, the light emitting partEMU of each of the first to third pixels PXL1, PXL2, and PXL3 isconfigured using light emitting elements of a same color (e.g., bluelight emitting elements), so that the manufacturing efficiency of thedisplay device can be improved.

The light scattering layer LSL may be provided to efficiently use lightof the third color (or blue) emitted from the light emitting element LD.In an example, in case that the light emitting element LD is a bluelight emitting element emitting light of blue, and the third pixel PXL3is a blue pixel, the light scattering layer LSL may include at least onekind of light scattering particles SCT to efficiently use light emittedfrom the light emitting element LD.

For example, the light scattering layer LSL may include light scatteringparticles SCT dispersed in a matrix material such as base resin. In anexample, the light scattering layer LSL may include a light scatteringparticle SCT such as silica, but the material forming the lightscattering particles SCT is not limited thereto. The light scatteringparticles SCT are not disposed in only the third pixel PXL3, and may beselectively included even at the inside of the first color conversionlayer CCL1 or the second color conversion layer CCL2. In someembodiments, the light scattering particle SCT may be omitted such thatthe light scattering layer LSL configured with transparent polymer isprovided.

A capping layer CPL may be disposed on the color conversion layer CCL.The capping layer CPL may be provided across the first to third pixelsPXL1, PXL2, and PXL3. The capping layer CPL may cover the colorconversion layer CCL. The capping layer CPL may prevent the colorconversion layer CCL from being damaged or contaminated due toinfiltration of an impurity such as moisture or air from the outside.

The capping layer CPL is an inorganic layer, and may include siliconnitride (SiN_(x)), aluminum nitride (AlN_(x)), titanium nitride(TiN_(x)), silicon oxide (SiO_(x)), aluminum oxide (AlO_(x)), titaniumoxide (TiO_(x)), silicon oxycarbide (SiO_(x)C_(y)), silicon oxynitride(SiO_(x)N_(y)), and the like.

A resonant filter RS may be disposed on the capping layer CPL. Theresonant filter RS may function to allow lights having severalwavelengths, which are emitted from the color conversion layer CCL, tobe selectively transmitted or reflected therethrough or therefrom bygenerating a multi-interference phenomenon, so that light efficiency canbe improved. In an example, the resonant filter RS may be a Fabry-Perotfilter, but the disclosure is not limited thereto.

The resonant filter RS may include a first resonant filter RS1 disposedin the first pixel PXL1, a second resonant filter RS2 disposed in thesecond pixel PXL2, and a third resonant filter RS3 disposed in the thirdpixel PXL3. In an embodiment, in case that the light emitting element LDis a blue light emitting element emitting light of blue, and the firstpixel PXL1 is a red pixel, light of red in light emitted from the firstcolor conversion layer CCL1 may be relatively transmitted by the firstresonant filter RS1, and light of blue in the light emitted from thefirst color conversion layer CCL1 may be relatively reflected by thefirst resonant filter RS1 to be recycled to the first color conversionlayer CCL1. For example, the first resonant filter RS1 may allow 70% ormore of the light of red to be transmitted therethrough, and allow 20%or less of the light of blue to be transmitted therethrough. Also, thefirst resonant filter RS1 may allow 10% or less of the light of red tobe reflected therefrom, and allow 60% or more of the light of blue to bereflected therefrom. However, the disclosure is not limited thereto.

In case that the light emitting element LD is a blue light emittingelement emitting light of blue, and the second pixel PXL2 is a greenpixel, light of green in light emitted from the second color conversionlayer CCL2 may be relatively transmitted by the second resonant filterRS2, and light of blue in the light emitted from the second colorconversion layer CCL2 may be relatively reflected by the second resonantfilter RS2 to be recycled to the second color conversion layer CCL2. Forexample, the second resonant filter RS2 may allow 70% or more of thelight of green to be transmitted therethrough, and allow 20% or less ofthe light of blue to be transmitted therethrough. Also, the secondresonant filter RS2 may allow 10% or less of the light of green to bereflected therefrom, and allow 60% or more of the light of blue to bereflected therefrom. However, the disclosure is not limited thereto. Asdescribed above, the light of blue is selectively reflected to berecycled in the first pixel PXL1 and the second pixel PXL2, so that theefficiency of the color conversion layer CCL can be improved.

In case that the light emitting element LD is a blue light emittingelement emitting light of blue, and the third pixel PXL3 is a bluepixel, light emitted from the light scattering layer LSL may betransmitted by the third resonant filter RS3.

The first resonant filter RS1 may include a first semi-transmissivelayer HMa1, a second semi-transmissive layer HMb1, and a medium MD1disposed between the first semi-transmissive layer HMa1 and the secondsemi-transmissive layer HMb1. The second resonant filter RS2 may includea first semi-transmissive layer HMa2, a second semi-transmissive layerHMb2, and a medium MD2 disposed between the first semi-transmissivelayer HMa2 and the second semi-transmissive layer HMb2. The thirdresonant filter RS3 may include a first semi-transmissive layer HMa3, asecond semi-transmissive layer HMb3, and a medium MD3 disposed betweenthe first semi-transmissive layer HMa3 and the second semi-transmissivelayer HMb3.

Each of the media MD1, MD2, and MD3 of the first to third resonantfilters RS1, RS2, and RS3 may include an organic material such asacrylic resin, epoxy resin, phenolic resin, polyamides resin, polyimidesresin, polyester resin, polyphenylene sulfide resin, or benzocyclobutene(BCB). Alternatively, each of the media MD1, MD2, and MD3 of the firstto third resonant filters RS1, RS2, and RS3 may include various kinds ofinorganic insulating materials including silicon oxide (SiO_(x)),silicon nitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y)), aluminumnitride (AlN_(x)), aluminum oxide (AlO_(x)), zirconium oxide (ZrO_(x)),hafnium oxide (HfO_(x)), and titanium oxide (TiO_(x)). Each of the mediaMD1, MD2, and MD3 of the first to third resonant filters RS1, RS2, andRS3 may include a transparent metal or a transparent metal oxide. In anexample, each of the media MD1, MD2, and MD3 of the first to thirdresonant filters RS1, RS2, and RS3 may include at least one of indiumtin oxide (ITO), indium zinc oxide (IZO), and zinc tin oxide (ZTO), butthe disclosure is not limited thereto.

Each of the media MD1, MD2, and MD3 of the first to third resonantfilters RS1, RS2, and RS3 may have a refractive index of about 2.5 orless. However, the disclosure is not limited thereto, and the refractiveindex of each of the media MD1, MD2, and MD3 of the first to thirdresonant filters RS1, RS2, and RS3 may be variously changed byconsidering a transmittance and/or a reflexibility of the resonantfilter RS and/or a spectrum of light emitted from the color conversionlayer CCL.

Each of the media MD1, MD2, and MD3 of the first to third resonantfilters RS1, RS2, and RS3 may be formed to have a thickness of about 1μm or less. However, the disclosure is not limited thereto, and thethickness T1, T2, or T3 of each of the media MD1, MD2, and MD3 of thefirst to third resonant filters RS1, RS2, and RS3 may be variouslychanged by considering a transmittance and/or a reflexibility of theresonant filter RS and/or a spectrum of light emitted from the colorconversion layer CCL.

Referring to FIG. 9 , a thickness T1 of the medium MD1 of the firstresonant filter RS1 in the third direction (Z-axis direction), athickness T2 of the medium MD2 of the second resonant filter RS2 in thethird direction (Z-axis direction), and a thickness T3 of the medium MD3of the third resonant filter RS3 in the third direction (Z-axisdirection) may be the same. For example, thicknesses of the first tothird resonant filters RS1, RS2, and RS3 in the third direction (Z-axisdirection) may be the same. As described above, in case that thethicknesses T1, T2, and T3 of the media MD1, MD2, and MD3 of the firstto third resonant filters RS1, RS2, and RS3 are formed equal to oneanother, fairness can be ensured.

Referring to FIG. 10 , a thickness T1 of the medium MD1 of the firstresonant filter RS1 in the third direction (Z-axis direction), athickness T2 of the medium MD2 of the second resonant filter RS2 in thethird direction (Z-axis direction), and a thickness T3 of the medium MD3of the third resonant filter RS3 in the third direction (Z-axisdirection) may be different from each other. For example, thicknesses ofthe first to third resonant filters RS1, RS2, and RS3 in the thirddirection (Z-axis direction) may be different from each other. AlthoughFIG. 10 illustrates as an example a case where the thickness T1 of themedium MD1 of the first resonant filter RS1 in the third direction(Z-axis direction) is greater than the thickness T3 of the medium MD3 ofthe third resonant filter RS3 in the third direction (Z-axis direction)and the thickness T2 of the medium MD2 of the second resonant filter RS2in the third direction (Z-axis direction) is greater than the thicknessT1 of the medium MD1 of the first resonant filter RS1 in the thirddirection (Z-axis direction), the disclosure is not limited thereto.

Each of the first semi-transmissive layers HMa1, HMa2, and HMa3 and/orthe second semi-transmissive layers HMb1, HMb2, and HMb3 of the first tothird resonant filters RS1, RS2, and RS3 may be a half mirror. Each ofthe first semi-transmissive layers HMa1, HMa2, and HMa3 and/or thesecond semi-transmissive layers HMb1, HMb2, and HMb3 of the first tothird resonant filters RS1, RS2, and RS3 may be a metal thin film havinga thickness of about 30 nm or less. In an example, each of the firstsemi-transmissive layers HMa1, HMa2, and HMa3 and/or the secondsemi-transmissive layers HMb1, HMb2, and HMb3 of the first to thirdresonant filters RS1, RS2, and RS3 may be formed as a single layer or amulti-layer, which is made of at least one of molybdenum (Mo), copper(Cu), aluminum (Al), chromium (Cr), gold (Au), silver (Ag), platinum(Pt), iron (Fe), titanium (Ti), nickel (Ni), neodymium (Nd), indium(In), tin (Sn), and any oxide or ally thereof, but the disclosure is notlimited thereto.

As shown in FIGS. 9 and 10 , the semi-transmissive layers HMa1 and HMb1of the first resonant filter RS1, the semi-transmissive layers HMa2 andHMb2 of the second resonant filter RS2, and the semi-transmissive layersHMa3 and HMb3 of the third resonant filter RS3 may be formed of a samematerial. In addition, the medium MD1 of the first resonant filter RS1,the medium MD2 of the second resonant filter RS2, and the medium MD3 ofthe third resonant filter RS3 may be formed of a same material. Asdescribed above, in case that each of the semi-transmissive layers HMa1,HMa2, HMa3, HMb1, HMb2, and HMb3 and the media MD1, MD2, and MD3 of thefirst to third resonant filters RS1, RS2, and RS3 are formed of a samematerial, the fairness can be ensured. However, the disclosure is notlimited thereto. As shown in FIG. 11 , each of the semi-transmissivelayers HMa1 and HMb1 and/or the medium MD1 of the first resonant filterRS1, the semi-transmissive layers HMa2 and HMb2 and/or the medium MD2 ofthe second resonant filter RS2, and the semi-transmissive layers HMa3and HMb3 and/or the medium MD3 of the third resonant filter RS3 may beformed of different materials.

The color filter layer CFL may be disposed on the resonant filter RS.The color filter layer CFL may be disposed directly on the resonantfilter RS, but the disclosure is not limited thereto. The color filterlayer CFL may include color filters CF1, CF2, and CF3 which accord witha color of each pixel PXL. The color filters CF1, CF2, and CF3 whichaccord with a color of each of the first to third pixels PXL1, PXL2, andPXL3 are disposed, so that a full-color image can be displayed.

The color filter layer CFL may include a first color filter CF1 disposedin the first pixel PXL1 to allow light emitted from the first pixel PXL1to be selectively transmitted therethrough, a second color filter CF2disposed in the second pixel PXL2 to allow light emitted from the secondpixel PXL2 to be selectively transmitted therethrough, and a third colorfilter CF3 disposed in the third pixel PXL3 to allow light emitted fromthe third pixel PXL3 to be selectively transmitted therethrough.

In an embodiment, the first color filter CF1, the second color filterCF2, and the third color filter CF3 may be respectively a red colorfilter, a green color filter, and a blue color filter, but thedisclosure is not limited thereto. Hereinafter, in case that anarbitrary color filter among the first color filter CF1, the secondcolor filter CF2, and the third color filter CF3 is designated or incase that two or more kinds of color filters are inclusively designated,the corresponding color filter or the corresponding color filters arereferred to as a “color filter CF” or “color filters CF.”

The first color filter CF1 may overlap the light emitting element layerLEL (or the light emitting element LD), the first color conversion layerCCL, and/or the first resonant filter RS1 of the first pixel PXL1 in thethird direction (Z-axis direction). The first color filter CF1 mayinclude a color filter material for allowing light of a first color (orred) to be selectively transmitted therethrough. For example, in casethat the first pixel PXL1 is a red pixel, the first color filter CF1 mayinclude a red color filter material.

The second color filter CF2 may overlap the light emitting element layerLEL (or the light emitting element LD), the second color conversionlayer CCL, and/or the second resonant filter RS2 of the second pixelPXL2 in the third direction (Z-axis direction). The second color filterCF2 may include a color filter material for allowing light of a secondcolor (or green) to be selectively transmitted therethrough. Forexample, in case that the second pixel PXL2 is a green pixel, the secondcolor filter CF2 may include a green color filter material.

The third color filter CF3 may overlap the light emitting element layerLEL (or the light emitting element LD), the light scattering layer LSL,and/or the third resonant filter RS3 of the third pixel PXL3 in thethird direction (Z-axis direction). The third color filter CF3 mayinclude a color filter material for allowing light of a third color (orblue) to be selectively transmitted therethrough. For example, in casethat the third pixel PXL3 is a blue pixel, the third color filter CF3may include a blue color filter material.

In some embodiments, a light blocking layer BM may be further disposedbetween the first to third color filters CF1, CF2, and CF3 or at aboundary between the first to third color filters CF1, CF2, and CF3. Asdescribed above, in case that the light blocking layer BM is formedbetween the first to third color filters CF1, CF2, and CF3, a colormixture defect viewed at the front or side of the display device can beprevented. The material of the light blocking layer BM is notparticularly limited, and the light blocking layer BM may be configuredwith various light blocking materials. In an example, the light blockinglayer BM may be implemented by stacking the first to third color filtersCF1, CF2, and CF3.

The overcoat layer OC may be disposed on the color filter layer CFL. Theovercoat layer OC may be provided throughout or across the first tothird pixels PXL1, PXL2, and PXL3. The overcoat layer OC may cover alower member including the color filter layer CFL. The overcoat layer OCmay prevent moisture or air from infiltrating into the above-describedlower member. Also, the overcoat layer OC may protect theabove-described lower member from a foreign matter such as dust.

The overcoat layer OC may include an organic material such as acrylicresin, epoxy resin, phenolic resin, polyamide resin, polyimide resin,polyester resin, polyphenylene sulfide resin, or benzocyclobutene (BCB).However, the disclosure is not limited thereto, and the overcoat layerOC may include various kinds of inorganic insulating materials includingsilicon oxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiO_(x)N_(y)), aluminum nitride (AlN_(x)), aluminum oxide (AlO_(x)),zirconium oxide (ZrO_(x)), hafnium oxide (HfO_(x)), and titanium oxide(TiO_(x)).

In accordance with the above-described embodiment, the resonant filterRS capable of allowing light having a specific wavelength to beselectively transmitted or reflected therethrough or therefrom isdisposed between the color conversion layer CCL and the color filterlayer CPL, so that light efficiency and luminance can be improved.

Hereinafter, an embodiment will be described. In the followingembodiment, components identical to those which have already describedare designated by like reference numerals, and repetitive descriptionswill be omitted or simplified.

FIG. 12 is a schematic sectional view illustrating first to third pixelsin accordance with an embodiment of the disclosure. FIGS. 13 to 15 areschematic sectional views illustrating a resonant filter.

Referring to FIG. 12 , a resonant filter RS may include a first resonantfilter RS1 disposed in the first pixel PXL1 and a second resonant filterRS2 disposed in the second pixel PXL1. The first resonant filter RS1and/or the second resonant filter RS2 may not overlap the third pixelPXL3.

In case that the light emitting element LD is a blue light emittingelement emitting light of blue, and the first pixel PXL1 is a red pixel,light of red in light emitted from the first color conversion layer CCL1may be relatively transmitted by the first resonant filter RS1, andlight of blue in the light emitted from the first color conversion layerCCL1 may be relatively reflected by the first resonant filter RS1 to berecycled to the first color conversion layer CCL1.

In case that the light emitting element LD is a blue light emittingelement emitting light of blue, and the second pixel PXL2 is a greenpixel, light of green in light emitted from the second color conversionlayer CCL2 may be relatively transmitted by the second resonant filterRS2, and light of blue in the light emitted from the second colorconversion layer CCL2 may be relatively reflected by the second resonantfilter RS2 to be recycled to the second color conversion layer CCL2.

In case that the light emitting element LD is a blue light emittingelement emitting light of blue, and the third pixel PXL3 is a bluepixel, the resonant filter RS may be omitted in the third pixel PXL3, sothat light of blue, which is emitted from the light scattering layerLSL, can be incident directly onto the third color filter CF3.

Referring to FIG. 13 , a thickness T1 of a medium MD1 of the firstresonant filter RS1 in the third direction (Z-axis direction) and athickness T2 of a medium MD2 of the second resonant filter RS2 in thethird direction (Z-axis direction) may be the same. For example,thicknesses of the first resonant filter RS1 and the second resonantfilter RS2 in the third direction (Z-axis direction) may be the same. Asdescribed above, in case that the thicknesses T1 and T2 of the media MD1and MD2 of the first and second resonant filters RS1 and RS2 are formedequal to each other, fairness can be ensured.

Referring to FIG. 14 , a thickness T1 of a medium MD1 of the firstresonant filter RS1 in the third direction (Z-axis direction) and athickness T2 of a medium MD2 of the second resonant filter RS2 in thethird direction (Z-axis direction) may be different from each other. Forexample, thicknesses of the first resonant filter RS1 and the secondresonant filter RS2 in the third direction (Z-axis direction) may bedifferent from each other. Although FIG. 14 illustrates as an example acase where the thickness T2 of a medium MD2 of the second resonantfilter RS2 in the third direction (Z-axis direction) is greater than thethickness T1 of a medium MD1 of the first resonant filter RS1 in thethird direction (Z-axis direction), the disclosure is not limitedthereto.

As shown in FIGS. 13 and 14 , semi-transmissive layers HMa1 and HMb1 ofthe first resonant filter RS1 and semi-transmissive layers HMa2 and HMb2of the second resonant filter RS2 may be formed of a same material. Inaddition, the medium MD1 of the first resonant filter RS and the mediumMD2 of the second resonant filter RS2 may be formed of a same material.As described above, in case that each of the semi-transmissive layersHMa1, HMa2, HMb1, and HMb2 and the media MD1 and MD2 of the first andsecond resonant filters RS1 and RS2 are formed of a same material, thefairness can be ensured. However, the disclosure is not limited thereto.As shown in FIG. 15 , each of semi-transmissive layers HMa1 and HMb1and/or a medium MD1 of the first resonant filter RS1 andsemi-transmissive layers HMa2 and HMb2 and/or a medium MD2 of the secondresonant filter RS2 may be formed of different materials.

In accordance with the disclosure, a resonant filter capable of allowinglight having a specific wavelength to be selectively transmitted orreflected therethrough or therefrom is disposed between a colorconversion layer and a color filter layer, so that light efficiency andluminance can be improved.

The above description is an example of technical features of thedisclosure, and those skilled in the art to which the disclosurepertains will be able to make various modifications and variations.Therefore, the embodiments of the disclosure described above may beimplemented separately or in combination with each other.

Therefore, the embodiments disclosed in the disclosure are not intendedto limit the technical spirit of the disclosure, but to describe thetechnical spirit of the disclosure, and the scope of the technicalspirit of the disclosure is not limited by these embodiments. Theprotection scope of the disclosure should be interpreted by thefollowing claims, and it should be interpreted that all technicalspirits within the equivalent scope are included in the scope of thedisclosure.

What is claimed is:
 1. A display device comprising: light emittingelements disposed in pixels; a color conversion layer disposed on thelight emitting elements; a color filter layer disposed on the colorconversion layer; and a resonant filter disposed between the colorconversion layer and the color filter layer, wherein the resonant filterincludes: a first semi-transmissive layer; a second semi-transmissivelayer; and a medium disposed between the first semi-transmissive layerand the second semi-transmissive layer.
 2. The display device of claim1, wherein the pixels include a first pixel, a second pixel, and a thirdpixel, and the resonant filter includes: a first resonant filterdisposed in the first pixel; and a second resonant filter disposed inthe second pixel.
 3. The display device of claim 2, wherein the firstresonant filter and/or the second resonant filter does not overlap thethird pixel in a plan view.
 4. The display device of claim 2, whereinthe resonant filter further includes a third resonant filter overlappingthe third pixel in a plan view.
 5. The display device of claim 2,wherein a thickness of a medium of the first resonant filter isdifferent from a thickness of a medium of the second resonant filter. 6.The display device of claim 2, wherein a thickness of a medium of thefirst resonant filter is equal to a thickness of a medium of the secondresonant filter.
 7. The display device of claim 6, wherein the pixelsinclude: a first pixel emitting light of a first color; a second pixelemitting light of a second color; and a third pixel emitting light of athird color, and the resonant filter allows the lights of the first tothird colors to be selectively reflected therefrom or transmittedtherethrough.
 8. The display device of claim 7, wherein the resonantfilter allows about 70% or more of the light of the first color and/orthe light of the second color to be transmitted therethrough, and allowsabout 20% or less of the light of the third color to be transmittedtherethrough.
 9. The display device of claim 7, wherein the resonantfilter allows about 10% or less of the light of the first color and/orthe light of the second color to be reflected therefrom, and allowsabout 60% or more of the light of the third color to be reflectedtherefrom.
 10. The display device of claim 9, wherein the medium of theresonant filter has a refractive index of about 2.5 or less.
 11. Thedisplay device of claim 9, wherein the first semi-transmissive layerand/or the second semi-transmissive layer is a metal thin film.
 12. Adisplay device comprising: first to third pixels respectively emittinglight of first to third colors; light emitting elements disposed in thefirst to third pixels; a color conversion layer disposed on the lightemitting elements; a color filter layer disposed on the color conversionlayer; a first resonant filter disposed in the first pixel between thecolor conversion layer and the color filter layer; and a second resonantfilter disposed in the second pixel between the color conversion layerand the color filter layer.
 13. The display device of claim 12, whereinthe first resonant filter and/or the second resonant filter allows thelights of the first to third colors to be selectively reflectedtherefrom or transmitted therethrough.
 14. The display device of claim12, wherein the first resonant filter and/or the second resonant filterdo/does not overlap the third pixel in a plan view.
 15. The displaydevice of claim 12, further comprising: a third resonant filter disposedin the third pixel between the color conversion layer and the colorfilter layer.
 16. The display device of claim 12, wherein a thickness ofthe first resonant filter is different from a thickness of the secondresonant filter.
 17. The display device of claim 12, wherein a thicknessof the first resonant filter is equal to a thickness of the secondresonant filter.
 18. The display device of claim 12, wherein the colorconversion layer includes: a first color conversion layer disposed inthe first pixel; a second color conversion layer disposed in the secondpixel; and a light scattering layer disposed in the third pixel.
 19. Thedisplay device of claim 12, wherein the light emitting elements emit thelight of the third color.
 20. The display device of claim 12, whereineach of the light emitting elements includes a first semiconductorlayer, a second semiconductor layer, and an active layer disposedbetween the first semiconductor layer and the second semiconductorlayer.